The rapid growth of the Internet and the proliferation of inexpensive digital media devices have led to significant changes in the way media is bought and sold. Online vendors provide music, movies, and other media for sale on websites such as Amazon, for rent on websites such as Netflix, and available for person-to-person sale on websites such as EBay. The media is often distributed in a variety of formats, such as a movie available for purchase or rental on a DVD or Blu-Ray disc, for purchase and download, or for streaming delivery to a computer, media appliance, or mobile device.
Internet companies that provide media such as music, books, and movies derive profit from their sales, and it is in their best interest to sell customers multiple items or subscriptions to provide an ongoing stream of profits. Netflix, for example, provides a subscription service to customers enabling them to rent or stream movies, and profits as long as subscribers continue to find enough new movies to watch to remain a subscriber. Pandora provides streaming audio in a customized music station format based on a customer's music preferences, deriving profit from either subscriptions or from advertising placed in limited free services. Amazon derives the majority of its profits from sale of physical media, and increases its profit from providing a customer with media recommendations similar to items that a customer has already purchased.
These media recommendations are typically made by employing a recommendation engine to identify media that is similar to other media in which a customer has shown an interest in, such as by purchasing, renting, or rating other media. Pandora, for example, uses an expert's characterization of a song using attributes such as structure, instrumentation, rhythm, and lyrical content to produce domain knowledge data for each song, and provides streaming songs matching identified customer preferences for one or more distinct customized stations based on its domain knowledge-based recommendation engine. Other media providers such as Netflix provide correlation-based recommendations, where user preferences for similar movies over a broad base of users and media are used to find preference correlation between the media and users in the database to recommend media correlated to other media a customer has liked.
Because the number of items purchased or the length of a subscription are related to the value a customer receives in continuing to interact with a media provider, it is in the provider's best interest to provide media recommendations that are accurate and well-suited to its customers. It is therefore desirable to provide the best quality media recommendations possible in a variety of media commerce environments.